The outbreak of COVID-19 in December 2019 in China has very quickly become a global health emergency with almost two million of infected patients worldwide.[1] Along with the spread of the pandemic, there has been a growing concern about the management of fragile rheumatic patients, for whom there is still very little data available. In particular, subjects affected by connective tissue diseases (CTD) are known to have an increased infectious risk compared to the healthy population due to a general impairment of the immune system intrinsic to the autoimmune disease itself, the iatrogenic effect linked to the use of immunosuppressive drugs, and the high number of comorbidities that often complicate the clinical picture.[2,3].We read with interest the Editorial by Cron and Chatam (1) suggesting a cytokine storm syndrome (CSS) occurring in response to SARS-CoV-2 infection and, consequently, a possible role for targeted approaches to blocking inflammatory cytokines.BACKGROUND Speeding is responsible for countless traffic collisions and road traffic injuries (RTIs) around the world. It threatens the lives of passengers in motor vehicles as well as the safety of other individuals sharing the public roads. https://www.selleckchem.com/products/apx-115-free-base.html Little evidence has been provided by low- and middle-income countries on speed transgression patterns. OBJECTIVE To document the prevalence of speeding in motor vehicles with four or more wheels and to analyse the associated factors in four Mexican cities. METHODS We conducted a cross-sectional study in the cities of Guadalajara-Zapopan, León, Cuernavaca and Villahermosa. Data on speed, drivers, vehicles, road infrastructure and the environment were collected from a randomly selected sample of urban road segments. We identified the factors associated with speeding through a logistic multiple regression model. RESULTS With an overall prevalence of 47% (95% CI 45.83 to 48.18), speeding occurred most frequently in Villahermosa (61.07%, 95% CI 59.10 to 63.01) as compared to León (51%, 95% CI 48.07 to 53.92), Cuernavaca (47.6%, 95% CI 45.35 to 49.85) and Guadalajara-Zapopan (20.76%, 95% CI 18.75 to 22.88). Speeding increased in the afternoons, on roads with numerous lanes, on Thursdays and Sundays and in foggy weather, but decreased in cities with speed control strategies and on roads with low visibility. No differences were observed between sexes or among age groups. CONCLUSIONS Evidence from our study highlights the urgent need to implement speed control measures such as changes in road infrastructure and design, and to promote comprehensive speeding legislation aimed at reducing exposure to this important risk factor. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.BACKGROUND Immigrants are at a higher risk of poor mental and physical health. Regular participation in physical activity (PA) and low levels of sedentary time are beneficial for both these aspects of health. The aim was to investigate levels and trends in domain-specific PA and sedentary behaviour in the US. immigrant compared with non-immigrant populations. METHODS From the 2007-2016 National Health and Nutrition Examination Survey (NHANES), a total of 25&nbsp;142 adults (?18&nbsp;years) were included in this analysis. PA and sedentary behaviour time were assessed by a questionnaire. RESULTS Transit-related PA showed downward linear trends in young immigrant adults (p trend=0.006) and middle-aged non-immigrant adults (p trend=0.009). We found significant upward linear trends in sedentary behaviour for both immigrants and non-immigrants across all age groups. For sitting watching TV or videos ?2&nbsp;hours/day, there was a downward linear trend in young immigrant adults (p trend=0.009). For computer use&nbsp;?1&nbsp;hours/day, an upward linear trend in older non-immigrants was found (p trend=0.024). Young immigrants spent 37.5 (95% CI -55.4 to -19.6) min less than non-immigrants on recreational PA&nbsp;per week. Also, older immigrants spent&nbsp;23.5 (95% CI 1.5 to 45.6) and 22.5 (95% CI 5.9 to 39.0) min/week more than non-immigrants on recreational PA and transit-related PA, respectively. Last, young and middle-aged immigrants spent 37.6 (95% CI -68.2 to -7.0) and 37.6 (95% CI -99.7 to -9.7) min/day less than non-immigrants on sedentary behaviour, respectively. CONCLUSION Overall, levels of recreational PA were stable, yet the transit-related PA declined coupled with an increase in sedentary behaviour. US. immigrants exhibit higher levels of transit-PA, lower levels of leisure-time PA and lower levels of sedentary behaviour, in some age groups. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.The ATP-grasp superfamily of enzymes shares an atypical nucleotide-binding site known as the ATP-grasp fold. These enzymes are involved in many biological pathways in all domains of life. One ATP-grasp enzyme, D-alanine-D-alanine ligase (Ddl), catalyzes the ATP-dependent formation of the D-alanyl-D-alanine dipeptide essential for bacterial cell-wall biosynthesis, and is therefore an important antibiotic drug target. Ddl is activated by the monovalent cation (MVC) K+, but despite its clinical relevance and decades of research, how this activation occurs has not been elucidated. We demonstrate here that activating MVCs bind adjacent to the active site of Ddl from Thermus thermophilus and used a combined biochemical and structural approach to characterize the MVC activation. We found that TtDdl is a Type II MVC-activated enzyme, retaining activity in the absence of MVCs. However, the efficiency of TtDdl increased ~20-fold in the presence of activating MVCs, and it was maximally activated by K+ and Rb+ ions. A strict dependence on ionic radius of the MVC was observed, with Li+ and Na+ providing little-to-no TtDdl activation. To understand the mechanism of MVC activation, we solved crystal structures of TtDdl representing distinct catalytic stages in complex with K+, Rb+, or Cs+ Comparison of these structures with apo TtDdl revealed no evident conformational change on MVC binding. Of note, the identified MVC-binding site is structurally conserved within the ATP-grasp superfamily. We propose that MVCs activate Ddl by altering the charge distribution of its active site. These findings provide insight into the catalytic mechanism of ATP-grasp enzymes. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.